Tunneling machine



TUNNELING MACHINE Filed March 16, 1931 8 Sheets-Sheet l INVENTOR r] TTUR/VE) July 12, 1932.

J. COMOLETTI TUNNELING MACHINE Filed March 16, 1931 8 Sheets-Sheet 2 July 12, 1932. J. COMOLETTI 1,866,753

TUNNELING MACHINE Filed March 16, 1931 8 Sheets-Sheet 3 July 12, 1932. .J; COMOLETTI TUNNELING MACHINE Filed March 16, 1951 8 Sheejzs-Shet 4 S) A INVENTOR W44 I A TTORNEY y 193/2- J. COMOLETTI 3 TUNNELING MACHINE Filed March 16, 1931 8 Sheets-Sheet 5 [N VENTOR ATTORNEY y 1932- .1; COMOLETTI TUNNELING MACHINE Filed March 16, 1931 s Sheets-Sheet 6 I N V E N T 0R fa/727 Gama/6 ffz' MTZQQY y 1932- J. COMOLETTI 1,866,753

TUNNELING MACHINE Filed March 16, 1931 8 Sheets-Sheet 7 INVENTOR A TTORNEY Patented July 12, 1932 UNITED STATES PATENT OFFICE JOHN COMOLETTI, OF LOS ANGELES, CALIFORNIA TUNNELING MACHINE Application filed March 16, 1931.

10 grate the earth, irrespective of the character of its formation, and a mounting for the drills which is operable to move the drills bodily while in engagement with the earth and in predetermined paths to cause the 15 drills to disintegrate the earth in the formation of a tunne It is also a purpose of my invention to provide a tunneling machine which embodies a vehicle upon which the drills are carried 2 and by which the drills are advanced to maintain them in operative engagement with the earth in order that they will distintegrate the earth as intended; the vehicle having a conveyor for conveying and elevating the disintegrated earth to the rear of the machine where it may be dumped into an awaiting car for removal from the tunnel.

I will describe only three forms of tun-. neling machines embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings:

Figure 1 is a view showing in side elevation one form of tunneling machine embodying my invention.

Figure 2 is a horizontal sectional view taken on the line 22 of Figure 1.

Figure 3 is a view showing the machine in front elevation with portions thereof broken away to reveal parts not otherwise shown.

Figure 4 is a fragmentary vertical sectional view taken on the line 4-4 of Figure 3.

Figure 5 is an enlarged fragmentary sectional'view taken on the line 55 of Figure 4:.

Figure 6 is an enlarged sectional view taken on the line 66 of Figure 2.

Figure 7 is a fragmentary sectional view taken on the line 7 -7 of Figure 6.

Figure 8 is a sectional view taken on the line 8-8 of Figure 2.

Serial No. 523,119.

Figure 9 is a view simil- .r to Figure 6 showing a modified form of drilling element and signals for the several elements of the machine.

Figure 10 is an enlarged fragmentary vertical sectional view taken on the line 10-10 of Figure 3.

Figure 11 is a semi-diagrammatic view showing in top plan the compressed air supply system for the several drilling elements of the machine.

Figure 12 is a fragmentary view showing in side elevation a second form of tunneling machine embodying my invention.

Figure 13 is a view showing in front elevation a third form of tunneling machine embodyingmy invention.

Figure 14 is a fragmentary view showing the machine of Figure 13 in side elevation.

Figure 15 is a view showing in top plan 7 the machine of Figures 13 and 14.

Figure 16 is a view similar to Figure 13 showing the earth digging elements in their uppermost positions as distinguished from the lowermost positions shown in Figure 13.

Figure 17 is an enlarged fragmentary vertical sectional view taken on the line 17'17 of Figure 15.

Figure 18 is an enlarged view showing the driving mechanism for actuating certain of the earth digging units of the machine shown in Figure 15.

Similar reference characters refer to similar parts in each of the several views.

In the form of my invention illustrated in Figures 1 to 11 inclusive, as well as in the other two forms of my invention the machine includes a vehicle which provides a mobile support for the earth digging or disintegrating units in order that they may be moved into engagement with the earth to be dug and advanced as the digging proceeds in order to maintain the digging units in operative engagement with the earth. The vehicle includes sides 15 maintained in spaced parallel relation by channel bars 16, and upon the sides is secured a top 17 which constitutes a platform upon which various parts of the mechanism of the machine are mounted. Rising from the platform 17 is a top or cover 18 which protects the machine against loosened earth falling on the mach ne and damaging its parts.

As" best illustrated in Figures 1, 2, and 10, a frame designated generally at F is secured to the forward ends of the sides 15 of the vehicle, and this frame includes bars 19 connected by a transverse bar 20, the bars 19 being fixed to the vehicle sides. Beyond the transverse bar 20, the bars 19 are curved downwardly, and in these curved portlons an axle 21 is journaled. Keyed to the opposite ends of the axle are the parallel portions 22 of a U-shaped frame F, the intermediate portion 23 of the frame carrying a multiplicity of earth digging elements E, and which elements in the present instance are in the form of pneumatic drills. These several elements together with the frame upon which they are supported constitute an earth digging unlt, and the present tunneling machine includes two such units one for digging the lower part of the tunnel and the other for digging the upper part of the tunnel.

As best illustrated in Figures 6 and 7, the frame portion 23 is provided at intervals along its length with transversely extending,

sockets 24 in each of which is received a drill or drilling element E, and it will be noted that these sockets are inclined so that the elements E when secured therein occupy corresponding positions for the purpose of rendering the drilling elements effective in the disintegration of earth. Each element includes a cylinder 25 in which works a piston havin a rod 26 projecting from the lower end of the cylinder and formed at its free end with a bit 27. The cylinder is secured in its respective socket 24 against circumferential movement by the provision of a rib 28 fitting within a corresponding groove 29 of the socket. For securing the cylinder against displacement from the socket, a set-screw 30 is provided.

The upper end of each cylinder 25 is connected to a length of hose 31 which supplies to the cylinder air under pressure from a distributing manifold 32 secured on the upper side of the frame portion 23 by means of brackets 33. As shown in Figure 11, this manifold 32 is of such length as to supply air under pressure to all of the drilling elements E, and, the manner in which air under pressure is generated and delivered to the distributing manifold, will be described hereinafter.

As illustrated to advantage in Figure 10, the axle 21 is adapted to be rotated to effect elevation of the frame F from the vertical position shown in Figure 10 to the horizontal position shown in dot and dash lines in Figure 1, or vice versa, by the provision of a shaft 34 provided with a worm 35 which constantly meshes with a worm wheel 36 fixed to the axle 21. This shaft 34 is suitably journaled on the vehicle and it extends rearwardly from the axle 21 for operative connection to a vertical shaft 37 which is journaled in and extends upwardly through the top or platform 17 of the vehicle. The lower end of the shaft 37-has fixed thereto a beveled gear 38 which constantly meshes with a air of similarly beveled gears 39 and 40 reely rotatable on the shaft 34. A clutch collar 41 is movable on the shaft 34, and it is provided with teeth 41a and 41?) at its opposite sides which engage similar teeth 41c and 4103 on the confronting sides of the gears 39 and 40 to positively be driven by either one gear or the other according as the clutch collar engages one gear or the other. In this manner the shaft 34 can be rotated by the shaft 37 and in one direction or the other. The clutch collar is manually operable through the medium of a rod 42 supported in suitable brackets at the side of the vehicle and connected to an operating lever 43. The lever is mounted so as to be within convenient reach of an operator occupying a platform 44 which projects from one side of the vehicle as best illustrated in Figure 2.

The upper end of the shaft 37 has fixed thereto a beveled gear 45 which constantly meshes with a pinion 46 fixed to the shaft of an electric motor 47. This motor is supported on and suitably fixed to the top or platform 17 of the vehicle, and as will be understood a suitable switch may be provided for controlling the supply of current to the motor from a suitable source to be described hereinafter.

The shaft 34 is also employed to drive the second earth digging unit designed for digging the upper part of the tunnel, and this unit is mounted to oscillate about a fixed axis. The unit comprises an arm 48 fixed at one end to a horizontal shaft 49 journaled in suitable bearings and, as shown in Figure .10, provided with a worm wheel 50 which constantly meshes with a worm 51 fixed on the upper end of a vertical shaft 52. The shaft 52 extends downwardly through the platform of the vehicle where it is provided at its lower end with a spiral gear 53 which constantly meshes with a similar gear 54 fixed to the shaft 34.

The arm 48 is provided with sockets in the same manner as the intermediate portion 23 of the frame F in order to receive a plurality of pneumatically operating drilling elements 55. Each element is constructed in the same manner as the elements E of the first earth digging unit, and they are adapted to be individually supplied with air under pressure from a distributing manifold 56 secured by brackets on the arm 48.

As best illustrated in Figure 2, a motor 57 is secured upon the platform 17 and operatively connected to an air compressor 58 for operating the latter. Air from the compressor is conducted to a storage tank 59 through a pipe 60, and from this tank a1r 1s supphed to the two distributing manifolds 32 and 56 through the pipes shown in Figare 11. As here shown, a ri id pipe 61 extends from the tank 59 to a exible pipe 62, the latter in turn being connected to the manifold 32 so as to supply air to the latter irrespective of the position of the frame F. 1nterposed in the pipe 61 is a valve 63 by which the supply of air from the tank to the man1- fold can be manually controlled.

A second rigid pi e 64 and a flexible pipe 65 connect the mani old 56 with the tank 59, and similarly the pi e 64 has a valve 66 interposed therein by which the supply of air from the tank to the manifold can be manually controlled. As will be observed in Figure 1, the two valves 63 and 66 are positioned to be within convenient reach of the operator occupying the platform 44.

A third motor 67 is secured on the platform 17, and this motor is provided for the pur ose of operating an endless conveyor for con ucting the dis ntegrated earth loosened from the walls of the tunnel by the earth digging units rearwardly through the vehicle and upwardly thereof so that it may be finally dumped into a car in the rear of the vehicle. As best shown in Figures 4 and 5, the conveyor comprises an endless belt 68 secured to a pair of endless chains 69 trained around sprockets 7O fixed to shafts 71 and 72 suitably journaled on the vehicle. A third sprocket wheel 73 is fixed to the upper shaft 71, and about this sprocket is trained an endless chain 74. The chain extends upwardly from the sprocket and is trained about a second sprocket 75 fixed to a shaft 76. Through the medium of beveled gears 77 the shaft 76 is operatively connected to the shaft of the motor 67.

The belt 68 of the conveyor is provided at intervals with transversely extending scoops 78 so positioned as to pick up earth delivered to a scoop-type of bucket 79 at the forward end of the vehicle, and under operation of the conveyor, the earth is carried upwardly thereof and finally dumped from the elevated end of this conveyor into a car, as illustrated in Figure 1. It will be noted that the positioning of the bucket 79 is such that as the vehicle is advanced into a tunnel the disintegrated earth will be scooped into the bucket so that the conveyor can elevate and convey the earth to the car at the rear of the machine.

The vehicle is adapted to be moved by the provision of conventional forms of endless tread chains 80 arranged at opposite sides of the vehicle and driven by a motor 81 operatively connected to one of the chain shafts in any suitable manner. The several motors provided for operating the various parts of the machine as well as the motor 81 for driving the tread chains are adapted to be supplied with current from a flexible cable 82 igure 1) which can be lengthened as the vehicle proceeds inwardly of the tunnel, as will be understood.

The operation of the machine just described is as follows:

With the two earth digging units in the normal positions shown in Figures 1 and 2, the frame F of the first unit occupies a vertical position so that the drilling elements are positioned adjacent the horizontal surface upon which the entire machine is operated. Assuming that each drilling element is supplied with air under pressure to effect reciprocation of the corresponding bit 27, the clutch collar 41 is now moved to operatively connect to the shaft 34 that gear which will effect rotation of the shaft in such direction as to rotate the axle 21 in a clockwise direction as when viewed in Figure 1. Under such movement of the axle, the frame F' is slowly elevated from the lowered vertical position and swung upwardly through an arc of substantially 180 to an upper vertical posit'on. During this movement of the frame, the several drilling elements operate to drill, dig or otherwise disintegrate the formation which the drill bits engage, the major portion of the bits cutting a portion of the vertical end wall of the tunnel, while the endmost bits engage and cut the sides of the tunnel, it being noted that the endmost bits are enlarged to extend beyond the ends of the frame F as illustrated in Figure 2.

Thus the lower earth digging unit is operable to cut away a portion of the sides of the tunnel as well as a portion of the inner end wall of the tunnel, and it will be understood that once the unit reaches its uppermost position it is restored to its starting or lowermost position by effecting rotation of the axle 21 in a counter-clockwise direction as when viewed in Figure 1.

Concurrent with operation of the lower earth digging unit, the upper earth digging unit is operated to cut the remainder of the sides of the tunnel, or those portions not cut by the lower digging unit, and also the remainder of the inner end wall of the tunnel. Under rotation of the shaft 49 in a clockwise direction as when viewed in Figure 2, the arm 48 of the unit slowly rises from its horizontal position and ultimately moves through an arc of substantially 180 to come to rest in a horizontal position at the opposite side of the shaft 49 from the normal or starting position of the arm. With the several drilling elements of the unit operating, it will be clear that under movement of the arm the elements function to dig, out, or otherwise disintegrate the earth at the sides and end wall of the tunnel, it being noted that as in the first unit, the second unit has a bit at the extreme end of the arm 48 which is elongated h to effect cutting of the sides and top of the tunnel.

Similarly, the lower digging unit upon completing its course of travel during the digging operation, can be returned to starting position by reversing rotation of the shaft 49. This operation takes place concurrently with the reverse movement of the lower digging unit, for it will be understood that when actuating the clutch collar 41 to cause reverse rotation of the shaft 34, the shaft 49 will llkewise be reversed in the direction of rotation. Thus the two digging units are simultaneously returned to normal or starting posi tion. By again actuating the clutch collar to effect rotation of the shaft 34 in the first direction, the two digging units can be again operated to effect a second digging operation. In this manner the machine operates to effect intermittent digging of the bottom sides and inner end wall to form a tunnel in which the entire machine can be accommodated, and a tunnel having walls which are symmetrical so that no further digging operations are necessary incident to lining the walls and setting up a suitable supporting structure to prevent caving-in 6f the walls of the tunnel.

The earth as dislodged from the walls of the tunnel, falls to the bottom thereof where it is collected in the scoop bucket 79, and with the conveyor continuously operating, the earth is removed from the bucket and finally discharged into the car at the rear of the vehicle. As the digging proceeds, it will be understood that the vehicle is advanced through operation of the tread chains so that the two digging units have proper operative engagement with the walls of the tunnel to effect digging thereof when operated.

By operating the entire machine through the medium of electric motors, pollution of the atmosphere. in a tunnel by exhaust gases from internal combustion engines is eliminated, and the purification of the air in the tunnel is promoted by the air exhausted from the several drilling elements to the end of providing suflicient oxygen for the operator.

In Figure 9, I have shown a modified form of mounting for the drilling elements of either digging unit designed for the purpose of effecting operation of signals to indicate to the operator of themachine when any one drilling element encounters an unusually hard formation which is cannot disintegrate, and so that the operator can take the necessary steps to remove this impassable formation from'the path of the digging unit. This mounting comprises the same socket 24 for the cylinder 25 of each drilling element, but the socket is open at its upper end and covered by a cap 83 bolted to the frame portion 23 or the arm 48. Through this cap extends the hose 31, and between the cap and the end of the cylinder 25 a coiled expansible spring 84 is interposed which operates to urge the cylinder downwardly within the socket. The cylinder is confined against displacement from the socket by the provision of a slotted extension 85 on the periphery of the cylinder, and a set-screw 86 which extends into the slot of the extension and abuts one end wall of the slot to prevent displacement of the cylinder from the socket. In providing the extension with a slot, the cylinder is permitted to move inwardly of the socket when the drill bit engages a formation which cannot be disintegrated. This inward movement of the cylinder is against the. tension of the spring 84, and it is utilized to close a switch for the operation of a signal.

The switch comprises a rod 87 secured to the inner end of the cylinder and moving in a suitable opening in the cap 83 to engage a contact 88 secured to and insulated from the cap. The rod and contact constitute the terminals of a circuit including a battery 89 and an incandescent lamp 90 so that when the switch is closed the lamp is illuminated. From a consideration of the diagrammatic showing in Figure 9 it will be clear that there is one lamp for each drilling element, the battery 89 supplying current to all of the lamps, and the illumination of any one lamp being controlled by the corresponding switch for the respective drilling element.

Referring now to Figure 12, I have here shown another form of tunneling machine embodying my invention which dispenses with the use of the upper earth digging unit in the first form of tunneling machine, and relies solely on the lower earth digging unit to dig all walls of the tunnel. This is accomplished by merely increasing the dimensions of the parts of the digging unit, that is to say, the frame F of the unit is enlarged longitudinally and transversely so that when it is moved through the arc of 180 it will dig all walls of the tunnel and produce a tunnel of suflicient height to accommodate the vehicle. In this embodiment of my invention the shaft 34 is disposed below the axle 21 instead of above as in the first form of tunneling machine, but the same operative connection is provided between the axle and the shaft in order that the axle may be rotated 180 in either direction.

Referring now to Figures 13 to 18 inclusive, I have here shown a third form of tunneling machine embodying my invention which employs the same vehicle, the same scoop bucket 79, the same drilling elements, and the same prime movers for the earth digging units, as in the other two forms of my invention. However, in the present embodiment, the digging units are arranged and operated in a different manner, as will now be described.

As in the other forms of my invention, the forward end of the vehicle is provided with a forwardly extending frame F, and journaled in this frame is a shaft 91 which can be rotated in either direction through the medium of the shaft 34. Also journaled in the frame F in advance of the shaft 91 is an axle 92 to which the parallel portions 93 of a U-shaped frame F are fixed so that by rotating the axle the frame as a Whole can be lowered or elevated. The intermediate portion 1 94 of the frame F carries three separate and distinct earth digging units D, D and D The unit D is fixed on the frame, disposed between the units D and D and provided with two drilling elements, as best seen in Figure 13. The units D and D are movable on the frame F to occupy one position in which they are parallel to the frame portion 94, and another position in which they are at right angles thereto and parallel to each other, as shown in Figure 16.

Each unit D or D comprises an arm 95 secured at one end to a stub axle 96 journaled in the frame portion 94. On the arm 95 are a plurality of pneumatically operated drilling elements E, and these elements are so arranged that 'when the two arms occupy vertical position the bits of the'elements are in confronting relation to each other, as shown in Figure 16. The stub axle 96 of one unit D is driven by a shaft 97 (Figures 15 and 18) through beveled gears 98, the shaft 97 being journaled in suitable bearings 99 carried by the frame F. The aforesaid stub axle is operatively connected to the stub axle for the other unit D by segmental gears 100 so that operation of one unit effects concurrent operation of the other unit.

The shaft 97 is adapted to be driven with the shaft 91 through the following mechamsm:

A spur gear 101 is keyed to the shaft 91 and constantly meshes with a similar gear 102 freely rotatable on the axle 92. This gear 102 is also movable longitudinally on the axle, and its hub is provided at one side of the gear with a toothed collar 103 which is adapted to engage a similar collar 104 fixed to the axle 92. Thus an operative connection is set up between the shaft 91 and the axle 92 for the purpose of elevating or lowering the frame F At the opposite side of the gear 102 the hub thereof is provided with an elongated collar 105 having an annular series of teeth 106 adapted to engage similar teeth on a collar 107. This collar 107 is freely rotatable on the axle 92 and is provided with a sprocket wheel 108 which is operatively connected to a similar wheel 109 fixed to the shaft 97 through an endless chain 110.

By the provision of the aforedescribed mechanism, it will be evident that according as the gear 102 is moved longitudinally on the axle 92 in one direction or the other, one collar 103 or the other 106 will engage the collar 104 or 107. Thus according as the gear 102 occupies one extreme position or the other on the axle 92 the axle itself is rotated to move the frame F, or the shaft 97 is rotated to effect actuation of the digging units D and D.

The collars 103, 104, etc., in reality constitute a double clutch, and it may be said that this clutch is operative to effect actuation of the frame F or the digging units D and D The intended operation of the frame and digglng units is such that the-shifting of the clutch should be automatic, and for this purpose the collar 105 is provided with a cam groove 111 into which extends a pin 112 on an arm 113. The contour of the groove 111 is such that when the collar 105 is rotated, the pin 112 will shift the clutch to one extreme position and then the other.

The frame F normally occupies the vertical position shown in solid lines in Figure 14, and it is adapted to be elevated to the horizontal position shown in dot and dash lines in the same figure. When reachin this last mentioned position it is automatlcall latched to prevent descent of the frame. therefore provide a spring pressed latch bolt 114. This bolt bears against a hub of one of the frame portions 93 so that when the frame occupies a horizontal position the latch bolt will engage a shoulder 115 on the hub and thus hold the frame in horizontal positlon. The latch bolt can be retracted to release the frame by the provision of a pedal 116 (Figure 14) which is o eratively connected to the latch bolt by a ca le trained over a pulley 117.

For supplying air under pressure to the drilling elements of all of the digging units, a flexible pipe 118 leads from the tank 59 to a rigid pipe 119 which is secured and extends down one frame portion 93 where itis connected to a main distributing manifold 120.

secured to the frame portion 94, all as clearly shown in Figure 13. From the manifold 120 three flexible pipes 121, 122, 123, extend to three manifolds 124, 125, and 126 secured on' the respective units D, D and D and con nected to the drilling elements by short lengths of hose.

For removing loosened earth from the inner end wall of the tunnel durin downward movement of the frame F, provide a scraper 127 pivoted on the rear slde of the frame portion 94 so that it can scrape the tunnel wall during ascent of the frame, as illustrated in Figure 14, and during descent of the frame to abut the frame and thus be extended beyond the drill bits to remove loose earth both from the end and bottom walls of the tunnel and move the loosened earth into the bucket 79.

The operation of the machine is as follows:

From the normal position shown in Figure 14, the frame F is slowly elevated to the horizontal position thereby imparting a corresponding movement to the three digging units D, D and D. 1 With the drilling elements of all of the units.operating,-it will be clear that the entire bottom, and a part of the sides and end walls of the tunnel will be drilled to remove earth therefrom. Once the frame F reaches horizontal position it is automatically latched by the bolt 114 so that it cannot return to its lower position. Upon the frame reaching latched postion, the clutch collar 105 has been rotated to effect shifting of the clutch to cause the teeth 106 to engage the teeth of the collar 107. Thus the axle 92 is no longer driven by the shaft 91, but the shaft now drives the shaft 97 through the intermediate chain and sprocket connection. vWith rotation of the shaft 97,-the stub axle 96 for the unit D is actuated to operate the segmental gears 100 and thus move the arms 95 from the normal horizontal position on the frame F to a vertical position, as illustrated in Figure 16.

-With the arms 95 slowly elevated and the corresponding drilling elements operating, it will be manifest that these two digging units function to drill the remainder of the side and end walls of the tunnel and also the top wall of the tunnel, it being noted that the outermost bits of the drilling elements project beyond the ends of the arms 95.

Once the arms 95 reach their uppermost position, the operator of the machine manipulates the clutch to effect reverse rotation of the shaft 34 to return the arms 95 to horizontal position and the entire frame F to lowered postion so that the units are now ready for a second operation. During descent of the frame F, the scraper 127 is automatically moved to active position by engag ing the loosened earth on the end wall of the tunnel so that it removes all loose earth from the wall and from the bottom of the tunnel finally delivering the loosened earth into the bucket 79.

Although I have herein shown and described, only three forms of tunneling machines embodying my invention, it is to be understood that various changes and modifications may be made therein without departing from the spirit of the invention and the spirit and scope of the appended claims.

I claim as my invention:

1. A tunneling machine, comprising two earth digging units, means for supporting the two units for swinging movement about a common horizontalaxis, and means for supportin'g'the two units for swinging movement on the first supportingmeans so that they can move about other horizontal axes which are at right angles to the first supporting axis.

2. A tunneling machine, comprising two earth digging units, means for supporting the two units for swinging movement about one axis, means for supporting the two units for swinging movement on the first supporting includingmeans for moving the units in opposed directions about the second mentioned axes.

3. A tunneling machine, comprising three earth-digging units, means for supporting the three units for swinging movement about a fixed horizontal axis, means on the supporting means for mounting two of the units for swinging movement about separate axes which are at right angles to the fixed horizontal axis, and mechanism for actuating the supporting and mounting means.

4. A tunneling machine, comprising three earth-digging units, means for supporting the three units for swinging movement about a fixed horizontal axis, means on the supporting means for mounting two of the units or swinging movement about separate axes which are at rightangles to the fixed horizontal axis, and mechanism for actuating first the supporting means and then the mounting means.

5. A tunneling machine, comprising two earth digging units, means for supporting the two units for swinging movement about a horizontal axis, means for supporting the two units for swinging movement on the first supporting means so that they can move about separate axes which are at right angles to the first supporting axis, and mechanism automatically operable to actuate the first supporting means to move the units upwardly to a horizontal osition, and then actuate the second supporting means to raise the units to a vertical position.

6. A tunneling machine comprising pneumatic drills arranged in two units, means for supporting the two units of drills for swinging movement about a fixed horizontal axis, means for mounting the two units of drills on the supporting means so they can move about separate axes at right angles to the supporting axis, means for supplying air under pressure to the drills and mechanism for actuating the supporting means and the mounting means. a

7. A tunneling machine comprising a support, a frame pivoted on the support to swing about a fixed horizontal axis, a air of bars supported by and pivoted on t e. frame to swing about axes at right angles to the frame axis, earth-digging elements on the bars, mechanism for elevating the frame to a horizontal position and swinging the bars to a port, aframe pivoted on'the support to swmg about a fixed horizontal axis, a pair of bars supported by and pivoted on the. frame to swing about axes at right angles to the frame axis, earth-digging elements onthe bars, and mechanism for first elevating the frame to a horizontal position and then swinging the bars to a vertical position.

9. A tunneling machine having a frame pivoted to swing about a fixed axis, sockets in the frame, a neumatic drilling element in each of the soc ets, the cylinder of which is movable lengthwise in the socket, a-spring for urging the cylinder outwardly of the socket, means for securing the cylinder against outward displacement from the socket, an electric signal, and a switch for supplying current to and actuating the signal, said switch being normally open and associated with the cylinder so as to be closed when the cylinder is forced inward against the tension of said spring.

10. A tunneling machine comprising a support, a frame pivoted on the support to swing about a horizontal axis, mechanism opera tively connected to the frame for swinging the latter upward from a depending vertical position, drilling elements on the frame,

means connected to the frame for actuating said elements as the frame ascends to dig earth in the path of the elements, a scoop bucket beneath said elements, scraper pivoted on the frame to engage as the frame descends earth loosened by the elements and move it into the bucket.

11. A tunneling machine comprising a plurality of earth digging units, means for supporting the units for movement parallel to one vertical plane, means for mounting the units on the supporting means formovement parallel to a second vertical plane at a right angle to the first mentioned vertical plane, and mechanism for actuating the supporting and mounting means.

12. A tunneling machine comprising a plurality of earth digging units, means for supporting the units for movement about one axis, means for mounting certain of the units on the supporting means for movement about a second axis at an angle to the first-mento the first mentioned horizontal axis, from tioned axis, and mechanism for actuating the supporting and mounting means.

13. A tunneling machine comprising a plurality of earth digging units, means for supporting the units for swinging movement about a horizontal axis from a depending vertical position to a substantially horizontal position, means for mounting the units on the supporting means for swmging movement about other horizontal axes at a right angle said horizontal position to an upstanding vertical position, and mechanism for moving the units together about the first mentioned axis and then in opposed directions about the second mentioned axes.

14. A machine for excavating a tunnel, the cross sectional contour of which is defined by and a.

cavating, the arched roof of the tunnel; and

mechanism for moving the excavating means first in one of said paths and then in the other.

JOHN COMOLETTI. 

